bug#71367: 30.0.50; ELPA package breadcrumb causes Emacs freeze when editing json file

[João Távora]

On Thu, Jun 6, 2024 at 12:33 PM Eli Zaretskii <eliz@gnu.org> wrote:

> I'd say allocate some initial space with make-vector, and then enlarge
> using vconcat or something?

That amounts to implementing VECTOR-PUSH/VECTOR-PUSH-EXTEND
for a new "dynamic vector" data type, very common in other languages.
Doesn't belong in breadcrumb at all, in fact doesn't even belong in
Elisp IMO, but
I don't  mind if someone contributes it there (after confirming
this is the culprit, of course).  Could even be some other package already
has it.